1. Field of the Invention
The present invention relates to a steering column for a vehicle, and more particularly to a steering column for a vehicle by which a manipulation convenience of the driver can be increased by performing a tilting or telescoping operation by using a pressure of air or oil without using an adjusting lever, and the number of components and manufacturing costs can be significantly reduced by easily adjusting an operating force of the actuator using a pressure of air or oil and an operating force of the lever according to the type of the vehicle.
2. Description of the Prior Art
In general, a steering column is an apparatus which surrounds a steering shaft transmitting a rotating force generated through manipulation of a steering wheel by a driver to a rack-pinion mechanism to support rotations of the steering shaft, and is coupled to a vehicle body through a bracket to fix a location of the steering shaft.
The steering column may further have a telescopic function or a tilting function for convenience of a driver. The tilt unit is a unit for adjusting a fixing angle of the steering wheel and the telescope unit is formed by coupling two hollow pipes to be extended or contracted in an axial direction thereof, and also has a function of absorbing impact energy while the steering shaft and the steering column are collapsed during a collision of the vehicle.
Thus, the steering apparatus may be classified into a telescopic or tilting steering apparatus according to a function thereof, and a tilting function may be added to the telescopic steering apparatus if necessary. A driver may adjust a protrusion degree or an inclination degree of the steering wheel in correspondence to a height or a body shape of the driver, smoothly manipulating a steering operation.
FIG. 1 is an exploded perspective view showing a part of a steering column for a vehicle according to the related art.
As shown in FIG. 1, the steering column for a vehicle according to the related art includes: an outer tube 100 accommodating a steering shaft 175; an inner tube 170 introduced into the outer tube 100; a lower mounting bracket 165 fixing the inner tube 170 to a vehicle body; an upper mounting bracket 105 installed at an upper side of the outer tube 100 to be fixed to the vehicle body; a distance bracket 180 integrally fixed to the outer tube 100 and having a telescope slot 185; a plate bracket 150 integrally formed with the upper mounting bracket 105 and in which a tilt slot 110 is formed to be long; a fixing gear 145 formed on an outer surface of the tilt bracket 150; an actuating gear 140 engaged with or disengaged from the fixing gear 145; a tilt bolt 130 passing through the tilt slot 110; a cam 135 engaged with the actuating gear 140; a washer 125 and a nut 120 fixing the cam 135 and an adjusting lever 115; and a gear spring 142 located between the actuating gear 140 and the fixing gear 145.
The tilting or telescopic operation is applied by fastening or releasing the adjusting lever 115 according to a principle in which the tilting or telescopic operation is not performed as the plate bracket 150 is narrowed to apply a pressing force to the outer tube 100 when the adjusting lever 115 is fastened so that the outer tube 100 and the inner tube 170 are attached to each other by a pressing force, and on the other hand, a pressing force between the outer tube 100 and the inner tube 170 disappears when the adjusting lever 115 is released, allowing a tilting or telescoping operation.
The telescopic operation is completed by releasing the adjusting lever 115, changing a location of the tilt bolt 130 along the telescope slot 185 formed in the distance bracket 180, and fastening the adjusting lever 115.
The tilting operation is completed by releasing the adjusting lever 115, changing a location of the tilt bolt 130 along the tilt slot 110, and fastening the adjusting lever 115.
While the outer tube 100 and the steering shaft 175 are fixed while the adjusting lever 115 is locked, the outer tube 100 and the inner tube 170 are tilted with respect to a tilt center 160 by the cam 135 or the steering column may be extended or contracted axially if the adjusting lever 115 is released.
However, the steering column for a vehicle according to the related art can perform a tilting or telescopic operation only when the adjusting lever is released or fastened by a force of a driver, deteriorating a manipulation convenience of the driver.
Further, loads are concentrated on the plate bracket and the distance bracket for fastening the steering column with the tilt bolt and the adjusting lever, so a support force and a strength of the column become vulnerable.
Further, in the steering column for a vehicle according to the related art, distributions of an actuating force of the adjusting lever become different according to a telescopic location, that is, a location of the telescope slot to which the tilt bolt is fixed during the tilting or telescopic operation.